Avaliação hidráulica da fundação de uma barragem de terra com tapete impermeável: estudo de caso da barragem Olho d’água

Abstract

According to Cedergren (1989) in the past, when it was common for designers to rely on intuition or rules to make decisions about a project exposed to erosive water processes, failures and malpractices were very common. Through the development of experimental and rational methods by scientists such as Casagrande and Terzaghi, designers began to have a better understanding of the properties of soil and earth foundations, thus being able to design more economical and safer engineering works. Even with the evolution of tests and studies in the area, it is still possible to observe the occurrence of selection of inadequate projects and the use of unsatisfactory draining materials. As explained above, the following work shows examples of statewide dams that present problems in their structures due to poorly controlled water flow, citing some flaws in the structures and interventions by their managers. This research also sought to investigate the problems in the Olho D’água dam located in the Várzea Alegre city, which presented two alternatives in its design phase, and the chosen project did not have a satisfactory operation, identifying several flow problems. After construction, the dam had to undergo intervention work by COGERH in order to control the flow and reduce the gradient at the foot of the slope. In order to evaluate the proposed dam structures and the intervention made therein, models of the executive projects and the section altered by COGERH in the Geostudio 2021 software were generated, which served to analyze the flow and slope stability under operating regime. It was observed that the original model, the first executive project developed by the company AGUASOLOS, presented good hydraulic behavior, in addition to excellent stability. On the other hand, the second executive project developed by CEC Engenharia, which was put into practice during construction, presented high output gradient values and stability very close to the recommended minimum of 1.5. Finally, the model with the intervention of COGERH, showed satisfactory results, indicating that the intervention had positive effects.